Mycoplasmal infection (MI) of cell cultures is a widespread problem that can invalidate diagnostic and experimental results. Many conclusions on MI are derived from studies on fibroblast cell cultures. The objectives of this research is to determine the relative efficiencies of detection methods in non-fibroblast cell cultures. Detection methods investigated include: microbiological inoculation, fluorescent DNA staining, immunofluorescence, scanning electron microscopy and indirect chemical methods. Cell Cultures studied will include: lymphocyte, endothelial, insect, neural, respiratory and urogenital. Mycoplasmas to be studied are: Mycoplasma, Acholeplasma, Spiroplasma and Ureaplasma. It is anticipated that results of these studies will have practical applications in the rapidly expanding field of differentiated cell culture and may be useful as models of in vivo mycoplasma infections.